package com.easy.util;

import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class ExpiryMap {
    //用来存储数据的容器
    private java.util.Map<String, Object> map = new java.util.HashMap<String, Object>();
    //存储数据的有效期
    private Map<String, Long> expiryMap = new java.util.HashMap<String, Long>();
    //检查过期线程(池)
    private ScheduledExecutorService service = Executors.newSingleThreadScheduledExecutor();
    //检查周期
    private long expiryTime = 1000 * 6 ;
    public ExpiryMap() {
        service.scheduleAtFixedRate(this::clearExpiry,expiryTime,expiryTime, TimeUnit.MILLISECONDS);
    }

    public ExpiryMap(long expiryTime) {
        this.expiryTime = expiryTime;
        service.scheduleAtFixedRate(this::clearExpiry,expiryTime,expiryTime, TimeUnit.MILLISECONDS);
    }

    public void put(String key, Object value) {
        map.put(key, value);
        expiryMap.put(key, System.currentTimeMillis() + expiryTime);
    }
    public void put(String key, Object value,long expiryTime) {
        map.put(key, value);
        expiryMap.put(key, System.currentTimeMillis() + expiryTime);
    }
    public Object get(String key) {
        if (expiryMap.get(key) < System.currentTimeMillis()) {
            map.remove(key);
            expiryMap.remove(key);
        }
        return map.get(key);
    }
    //清除掉过期的Key
    public void clearExpiry(){
        for (String key : expiryMap.keySet()) {
            if (expiryMap.get(key) < System.currentTimeMillis()) {
                map.remove(key);
                expiryMap.remove(key);
            }
        }
    }
}